Characterization of the carrier-mediated transport of ketoprofen, a nonsteroidal anti-inflammatory drug, in rabbit corneal epithelium cells
Version of Record online: 7 SEP 2012
© 2012 The Authors. JPP © 2012. Royal Pharmaceutical Society
Journal of Pharmacy and Pharmacology
Volume 65, Issue 2, pages 171–180, February 2013
How to Cite
Fujii, S., Hayashi, H., Itoh, K., Yamada, S., Deguchi, Y. and Kawazu, K. (2013), Characterization of the carrier-mediated transport of ketoprofen, a nonsteroidal anti-inflammatory drug, in rabbit corneal epithelium cells. Journal of Pharmacy and Pharmacology, 65: 171–180. doi: 10.1111/j.2042-7158.2012.01583.x
- Issue online: 26 DEC 2012
- Version of Record online: 7 SEP 2012
- Manuscript Accepted: 21 JUL 2012
- Manuscript Received: 1 MAR 2012
- monocarboxylate transporter;
- organic anion transporter;
- rabbit corneal epithelial cells
Using rabbit corneal epithelial cells (RCECs), the transport of a nonsteroidal anti-inflammatory drug (NSAID) [3H]ketoprofen across the cornea was investigated with the aim of revealing the mechanism of uptake.
[3H]Ketoprofen transport was evaluated by measuring the permeability across the RCECs layers.
[3H]Ketoprofen uptake was time, temperature and pH dependent. Maximal uptake occurred from a solution with a pH of 5.25. Uptake was also reduced by metabolic inhibitors (sodium azide and dinitrophenol (DNP)) and proton-linked monocarboxylate transporter (MCT) inhibitors (carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) and α-cyano-4-hydroxycinnamic acid (CHC)). [3H]Ketoprofen uptake was significantly inhibited by various monocarboxylates and other NSAIDs and by MCT and/or organic anion transporter (OAT) inhibitors probenecid and p-aminohippurate, but was unaffected by organic anion-transporting polypeptide (OATP) inhibitors bromosulfophthalein and taurocholate. The specific uptake of [3H]ketoprofen was saturable. Eadie–Hofstee plots indicated the involvement of high- and low-affinity components. The Km and Vmax values for the high- and low-affinity components of [3H]ketoprofen uptake were 0.56 and 24 mm, and 0.37 and 61 nmol/min/mg of protein, respectively. Benzoic acid, a substrate and inhibitor of MCTs, selectively inhibited low-affinity [3H]ketoprofen uptake. Conversely, indometacin inhibited high-affinity [3H]ketoprofen uptake.
The results of this study suggest that the monocarboxylate transport system partly accounts for the low-affinity component of [3H]ketoprofen uptake, and that the carrier-mediated transport systems such as the OAT family, shared by NSAIDs account for the high-affinity component.